1. Field of the Invention
The present invention is directed toward the field of graphics, and more particularly toward rendering multi-layer data on an output display.
2. Art Background
It is typical for graphics applications to manipulate large source images for display on a computer. For example, a source image may consist of many mega-pixels of image data. The graphics application typically operates within a broader application. For example, software, which allows a user to view and manipulate multi-level integrated circuit (“IC”) designs, utilizes a graphics application. The underlying source image for the IC design application is large, and thus the source image can't be displayed entirely on a computer display at full resolution.
In imaging applications, it is important to display images at various resolutions. For example, images are displayed at high resolutions so that image details may be visible. In addition, graphics applications require display of images at low resolutions. Since large source images can't be viewed at full resolution on a typical computer display, displaying the image at low resolutions permits viewing of large portions of the image. Typically, the IC design software permits the user, through use of a user interface, to pan large IC designs to permit viewing desired portions of the design. In addition, the IC design software permits the user to view the IC designs or portions of the IC designs at different resolutions.
Electronic design automation (“EDA”) applications assist engineers in designing integrated circuits. Specifically, these applications provide sets of computer-based tools for creating, editing, and analyzing IC design layouts. The IC design layouts are formed by geometric shapes that represent layers of different materials and devices on IC's. For instance, geometric shapes are defined to represent conductive interconnect lines. Interconnect lines route signals on the IC's. These lines are sometimes referred to as wire segments.
The IC designs represent different layers of an IC, and thus the graphical data to represent the IC designs includes multi-layer data. Typically, a user of the IC design software may desire to view one or more layers of the IC design. The IC design software may provide a means for the user to activate or deactivate different layers of the IC design to view a new modified image. Typically, in prior art systems, substantial computation is required to render a new image with the activated or deactivated layers. Accordingly, it is desirable to develop a graphics system that readily renders images for multi-layer data.